The use of surgically implanted ports as a means of enhancing drug delivery to desired patient locations is known. Typically, the port comprises a container that forms a reservoir with a resilient or rubberized septum on the access side nearest the skin and a rigid surface on a side opposite. The port also has a outlet tube through which any drugs or fluids that are deposited in the reservoir may flow outwardly to reach the desired organ or circulatory target. Physicians will frequently implant a port in an area to which the port can easily be accessed, and will frequently utilize the port for numerous drug administrations. The fact that the port is implanted is beneficial in that administered drugs will more selectively reach their target areas. Likewise, by being surgically implanted, accessing the port as opposed to directly administering drugs through a vein or other bodily tissue reduces the chance of the health practitioner of acquiring a blood-borne or other communicable disease.
However, certain problems exist with current devices and methods utilized to access surgically implanted ports. Usually a port is accessed by means of a catheter. The catheter is usually inserted into the septum by means of a hollow needle syringe that is received inside the catheter. Unfortunately, the use of a hollow needle causes coring in the septum and as a result, may cause the septum to leak medicines or other fluids intended to be targeted for other bodily areas. Consequently, the septum of the port becomes ineffective at retaining the drugs they are intended to hold, thus requiring more frequent drug administrations as well as premature replacement of the port.
Additional problems that can occur when trying to catheterize a surgically implanted port are the phenomenon of axial compaction and crimping. Axial compaction occurs when the catheter, while axially surrounding a needle, slides up the needle when the catheter and needle are inserted through soft tissue and into the septum of the port. The result of such compaction is that the catheter does not become fully inserted into fluid contact with the reservoir of the port and, as a result, fails in its intended purpose to administer drugs into the reservoir of the port. Crimping occurs when the catheter, once inserted, is bent to configure with the body of the patient. Conventional catheters, as a result of crimping, oftentimes become closed, thereby being incapable of allowing drugs or fluids to flow freely into the port and often must be replaced.
Still of further disadvantage of the current devices and methodology used to access ports is the risk involved to administering personnel with inadvertent needle-stick experiences. While the use of implanted ports is somewhat effective in limiting the amount of blood and tissue that is encountered while administering a drug through injection, a substantial risk is still present as the needles that are inserted into the septum do, in fact, come into contact with bodily fluids that may contain infective microbiological agents. More notably and commonly associated with these blood-borne diseases are AIDs and hepatitis B, which have the capability to infect an individual through such an inadvertent needle-stick experience. Accordingly, there is a need to minimize the risk that is involved for a potential needle-stick situation when inserting a catheter into such a surgically implanted port.
Not only is there a need to minimize the risk of a needle-stick experience, there is also a need for greater accuracy when inserting the needle and catheter into the septum. The traditional method of using a syringe axially surrounded within a catheter has the disadvantage of not providing the individual seeking to catheterize the port with any means of guiding and supporting the catheter into the port. As a result, problems can arise where the catheter and needle bend or deflect during insertion, thereby missing the port reservoir.
Attempts to remedy these problems have recently been made. U.S. Pat. No. 5,135,502 shows an apparatus for inserting a catheter within a surgically implanted port. The invention uses a solid stylet which is effective in preventing the coring of the septum of the port. Furthermore, the invention attempts to provide greater accuracy in inserting the needle and catheter into the implanted port as well as provide a means of preventing needle sticks upon retraction of the stylet. However, greater accuracy in inserting the needle and catheter as well as greater capability in preventing the risk of needle-stick experiences is still in need of further refinement.
Accordingly, there is a need to remedy the defects associated with the current methodology and devices used for catheterizing a surgically implanted port. Furthermore, there is a need to provide greater support and accuracy when inserting a catheter into a surgically implanted port as well as provide a more reliable means of enclosing the stylet upon retraction so as to prevent any risk of potential needle-stick experiences.